Cobalt-loaded cherry core biochar composite as an effective heterogeneous persulfate catalyst for bisphenol A...

Persulfate (PS)-based advanced oxidation processes have drawn tremendous attention for the degradation of recalcitrant pollutants, and cobalt composites are effective for PS activation to generate reactive species. In this study, composites of cobalt species loaded on cherry core-derived biochar (Co/C) were prepared with a one-step pyrolysis method. The Co/C catalyst was applied as a catalyst for PS activation to degrade bisphenol A (BPA). Factors influencing the degradation efficiency were examined, including the ratio of raw materials, Co/C and PS dosages, temperature, and solution pH. The Co/C catalyst prepared when the ratio of raw material was 1 : 1 (Co/C-50) could efficiently activate both peroxymonosulfate (PMS) and peroxydisulfate (PDS). When the initial concentration of BPA was 20 mg L^-1, complete removal of BPA was achieved in the Co/C-50-PMS and Co/C-50-PDS systems within 8 min and 10 min, respectively. More than 70% of BPA could be mineralized in the Co/C-50-PS system. The free radical quenching experiments demonstrated that in the Co/C-50-PS system, the degradation of BPA was achieved through free radical, surface-bound free radical, and non-free radical pathways. The successful preparation of the Co/C-50-PS catalyst broadens the application of cobalt-based carbon materials in the activation of PS to remove organic pollutants.